PROCESS DESCRIPTION:
Gas turbine generators:
Power Generation Package (GTG) is composed of gas turbine and turbo generator. MP fuel gas is supplied from fuel gas unit is burnt in gas turbine to generate mechanical energy which is used to drive electrical generator.
Parts of Gas turbine generator:
The essential parts of Gas turbine generator are listed below
• Engine Air compression system
o Compressor stator
o Compressor rotor
• Combustion system
o Fuel nozzles
o Spark plugs
o Flame detector
• Turbine section
o H.P Turbine section
▪ Turbine casing
▪ First and second stage turbine nozzle
▪ First and second stage turbine wheel
▪ Bearings
o L.P Turbine section
▪ Transition duct
▪ First and second stage turbine casing
▪ L.P exhaust frame
▪ Discharge diffuser
▪ Exhaust plenum
▪ L.P rotor
▪ Bearings
• Auxiliary section
o Accessory gear
o Coupling
o Inlet and exhaust system
o Lube oil system
o Ventilation system
o Cooling and sealing air system
o Washing system
Engine air compression section:
The aerodynamic design of this section functions to achieve top performance while keeping the number of stages to a minimum. The primary purpose of the compressor section is to compress air for combustion. Air taken in through the inlet passes through successive stages of compressor rotor blades and compressor stator vanes and is compressed as it passes from one to the next. After passing through the 11 stages, the air has been compressed to a ratio of 17:1.
The position of the compressor IGV and VSVs are controlled as function of compressor speed by the control panel.
Major components of compressor section are:
• Compressor stator.
• Compressor rotor.
Combustion Section:
The combustion system is of the multi-can, reverse flow type, with six cans mounted on the compressor discharge casing. In each combustion chamber there are 5 fuel nozzles, each of them containing a premixing tube (where fuel gas and air mix together before the burning zone) and a central body with a diffusion fuel gas circuit.
The combustion section consists of:
• Six combustion chambers.
• Six transition pieces.
Turbine section:
The H.P. turbine section is directly coupled to the HP turbine rotor. It is a two-stage turbine with air cooled nozzles and buckets that were designed to obtain high efficiency over a wide power range.
The H.P. turbine section consists of:
• Turbine casing.
• First stage turbine nozzle.
• Second stage turbine nozzle.
• First and second stage turbine wheels.
The L.P. turbine section consists of:
• Transition duct.
• First and second stage turbine casing.
• L.P exhaust frame.
• Discharge diffuser.
• Exhaust plenum.
• L.P rotor.
• Bearings.
Auxiliary section:
The following are the auxiliary section involves in Gas Turbine Generator (GTG).
Accessory gears:
The accessory gear assembly is a gear box coupled directly to the turbine rotor and it is used to drive the turbine-driven accessory devices.The accessory gear, located on the base, contains the gear trains required to provide gear reductions to drive the accessory devices at required speeds.
Coupling:
The basic functions of the flexible gear type couplings used on this turbine are to:
a) Connect two rotating shafts in order to transmit torque from one to other.
b) Compensate for all three types of misalignment (parallel, angular and combination of both).
c) Compensate for any axial movement of the shafts so that neither exerts an excessive thrust on the other.
Two couplings are used on this turbine:
• One connects the accessory drive gear with the turbine shaft.
• Other connects the turbine shaft with the load equipment.
Inlet and Exhaust system:
Gas turbine performance and reliability are a function of the quality and cleanliness of the inlet air entering the turbine. Therefore, for optimum operation, it is necessary to treat the atmospheric air entering the turbine and filter out the contaminants. The air inlet system, with its specially designed equipment and ducting, modifies the quality of the air under various temperature, humidity and contaminants.
Hot exhaust gases produced as a result of combustion in the turbine are attenuated in the exhaust system ducting before being released to the atmosphere or to a waste heat recovery unit.
Mineral Lube Oil System:
The gas turbine is lubricated by a closed loop, forced feed oil system which includes an oil tank, pumps, heat exchangers, filters, valves and miscellaneous devices which offer control and protection to the system. Lube oil from the system is circulated to the the four main turbine bearings, turbine accessories and driven load equipment.
Ventilation system:
The ventilation system provides ventilation to the auxiliary, auxiliary gear, turbine and coupling compartments to prevent over temperature condition and accumulation of hazardous gases.
Cooling and Sealing air system:
The cooling and sealing Air system supplies cooling air to the aft side of the second stage wheel space of H.P. turbine, the forward and aft sides of first and second stage wheel spaces of L.P. turbine, cooling for the L.P. turbine exhaust frame struts and sealing air for the lube oil seals of all the gas turbine bearing lube oil seals by means of the axial compressor fourth stage extraction.
Washing system:
The on-line / off-line washing is provided to clean axial compressor blades, removing deposists and ensuring the restoration of efficiency and it’s substantially composed of
• Water washing skid (or trolley) including,
o Washing solution tank.
o Washing fluid pump, driven by electric AC motor.
o Electric heater.
o Local control panel.
o Water washing drain water tank.
• Solenoid valves.
• Water washing on-line and off-line manifold.
Very nice
ReplyDeleteNice
ReplyDeleteAwesome
ReplyDelete